America never invaded Afghanistan

How is bombing kabul to rubble showing restraint? But I guess even if they didn't go ona  full-scale invasion, things wouldn't have changed much. Iraq would still be enough of a blow to US-muslim relations. 1.6 million deaths is a lot more than the toll of Afghanistan.

Iran would probably have more problems to deal with in its Eastern provinces, since the Taliban may have been able to stay in power.

Because they knew it would be a long and difficult war in a country recognised as the graveyard of invading armies

In the long run it might have improved US-Arab relations as Muslims, horrified by the unprovoked attacks, made efforts to distance themselves from the extremists. Afghanistan would be isolated and contained like Gadaffi's Libya after the Lockerbie bombings, or Iraq after the Gulf War, with economic sanctions and occasional bombing raids on Omar's property in retaliation. Eventually the people, sick of Taliban oppression, would rise up and overthrow the tyrant, as happened during the recent Arab Spring. America could supply the militias and use drones to help mop up the surviving Taliban before they can retreat into the mountains

I'd say without the events of the past several years, there would be no 'Arab spring'. I'm not sure why delivering Egypt into military rule should be considered a 'spring' either.

Originally posted by Nick1986 In the long run it might have improved US-Arab relations as Muslims, horrified by the unprovoked attacks, made efforts to distance themselves from the extremists. Afghanistan would be isolated and contained like Gadaffi's Libya after the Lockerbie bombings, or Iraq after the Gulf War, with economic sanctions and occasional bombing raids on Omar's property in retaliation. Eventually the people, sick of Taliban oppression, would rise up and overthrow the tyrant, as happened during the recent Arab Spring. America could supply the militias and use drones to help mop up the surviving Taliban before they can retreat into the mountains

Yes, but I think the US wants to control and extract the huge natural resources found in Afghanistan. It seems Afghanistan sits on mines of valuable minerals such as gold, iron, copper, coal and various precious stones.
http://www.aolnews.com/2010/06/14/report-afghanistan-sitting-on-goldmine-literally/
And of course, how can one forget another valuable material, opium. Though the US has been trying to convince farmers to grow other crops, mainly to cut the Taliban's main income, opium is valuable for its use in the pharmaceutical industry. Many anti-depressants and pain-killers are derived from opium.

I don't see how a blockade would have enabled the US to tap into all of these resources.